Power plug has been a basic equipment in a car for many years. With increasing demand from drivers and passengers, many devices requiring power supply, including an audio, mobile phone, and so on, have been in great use, apart from the conventional cigarette lighter. Consequently, the demand of power plug is increased and its usage has been greatly enhanced.
The power plug (i.e. widely known as a cigar or cigarette lighter) is disposed with a protruding electrode from its center and the other electrode on its both sides or its circumference, both of which are connected with the respective pole in the cigarette lighter to form a closed circuit. The power is usually a direct current of 12V.
The conventional power plug as described above has a centrally protruding electrode and the other electrode comprising two outward stretching spring plate on the respective side of the power plug; other portion is made of electrically insulating material. Leads are then used to connect the power plug with peripheral devices, such as CD player, mobile recharging seat, and so on.
In order to control the connection/disconnection for the power of the peripheral devices, some companies have installed a switch on the positive pole, a unitary push-on switch with modular design. Although the push-on switch may achieve the expected connection/disconnection function for the power supply, the ampere supplied by the power switch is low, 3 to 5 amperes for example, due to its structural factors. Such a low current is usually not enough to supply certain peripheral devices, such that this kind of power plug cannot be widely applied. Furthermore, this unitary push-on switch is usually manufactured by professional manufacturers with a high price tag, leading to a mounting cost for the power plug manufactures and thus a decreased profit for them. These two factors have posed a great barrier for the wide application of the vehicle power plug.
Consequently, it is necessary to design a new power plug to overcome the drawbacks described above.